Method of treating argentiferous lead ores.



0. H. PIGHER.

METHOD OF TREATING ARGENTIFEROUS LEAD ORES.

APPLICATION EILEE JULY 3, 1905. RENEWED SEPT. so, 1908.

Q 920,388, Patented May 4, 1909.

W! NESSES w INVEN K; ATTORNEY.

' tory furnace. This reliminary roasting of UNITED s ATns PATENT OFFICE.

OLIVER H. PIOHER, OF JOPLIN, MISSOURI.

METHOD OF TREATING ARGENTIFEROUS LEAD ORES.

Specification of Letters Patent.

Patented m 4, 1909.

Application filed July 3, 1905, Serial No. 268,080. Renewed September so, 1908. Serial No. 455,395.

To all whom it may concern:

Be it known that I, OLIVER H. PIOIIER, a citizen of the United Statesof America, residing in Joplin, in the county of Jasper, in the State of Missouri, have invented a certain new and usefulImprovement in Methods of argentiferous lead ores containing sulfur and has for its object the economical utilization of such ores for the production of nonargentiferousv lead products, preferably pig lead and sublimed White lead and of desulfurized argentiferous products suitable for further treatment for the production of silver and lead.

Sulfid ores containing lead and silver have hitherto been treated for the extraction of their metallic values in the best practice by processes which involved a preliminary roasting of the ores to drive off their contained sulfur, such roasting either taking place in a roasting furnace or as a preliminary stage of the treatment in a reverberathe ores results in t e loss of considerable percentages of their metallic values and of expense. In the case ofnon-argentiferons lead ores containing sulfur it is Well known that such ores can be successfully treated withdesulfurization in open hearth furnaces for the-partial reduction and partial sublimation of their lead contents, the fume beihg caught in screens and afterward treated for the production of lead or lead and sublimed white lead, butargentiferous ores have not heretofore been used in this way because of the well known fact that a material percentage of their silver contents would be driven from the furnace with the lead fume and presumably lost. I have discovered that by treating such sulfid ores without previous desulfurization in an open hearth furnace and at comparatively low temperature there is produced, in addition to'the silver hearing or gray slag and argentiferous base bullion, an argentiferous dust and the blue fume of lead compounds and carbon dust which dust and fume issue from the furnace with the gases and can be practically entirely separated from each otherby subsidence of the dust in a'system of flues and settling chambers so that at the end of such flue system the furnace gases and blue fume are practically non-argentiferous. The fume is then separated by screening from the furnace gases and subsequently treated for the recovery of its non-argcntiferous lead contents and preferably in a sublimation furnace for the production of pig lead and sublimed white lead. The argentiferous slag and dust from the furnace and flues is in good condition for subsequent treatment and the economical recovery of the silver and other metallic contents therefrom by any of the usual well known methods.

In the drawing in which I have illustrated a plant suitable for use in connection with my new process, Figure 1 is a dia rammatic representation of a plant suitable for the carrying out of my irocess, the portion at the right side of the drawing being shown. in

smaller scale than the remainder of the fig- A, A, A, are open hearth furnaces of the Scotch hearth type, B, is a horizontal flue leading from said furnaces and provided with a series of dust collecting hoppers C, C, etc. leading to a system of cooling flues D, having dust collecting chambers connected therewith, as shown at E, E, etc.

F, is a fan used to draw the gases and fumes through the flues and to force them through the flue G, into the fabric screens orbags H.

In practical operation the sulfid ore of lead and silver in admixture with carbon is treated in' the open hearth furnaces, the treatment bein such that a compound reducing and oxi izing action is obtained, and at a comparatively low temperature. The gaseous products of the furnace together with the admixed dust and fume are carried through the system of settlmg and cooling flues to effect the se aration of the argentiferous dust by subsi ence and thecooling of the gases, and the ractically nonargentiferous blue fume 1s nally separated from the gas by, the screen system.

The recovered blue fume is treated for the recovery of its non-argentiferous lead contents in any convenient way, preferably after being burned in the well known way to form crusts or cinders for further furnace treatment, it is then 'SubJected to a comsu hmed white lead which is separated from the furnace gases by screens in the well known manner.

The material advantage of my new process lies in the economical extraction of metal and metallic oroducts from the sulfid ores of lead and si er, the economies residing chiefly in the facts, first, that I treat the raw orewithout previous desulfurization and recover practically all of its metallic contents and, second, that I produce from such ores a non-argentiferous sublimed white lead which has heretofore been unattainable from such sources and which is a valuable product, and which, if considered as a by-product, materially lessen the cost of treating the ore as contrasted with previous methods for treatment of such ores.

Having now described my invention, What I claim as new and desire to secure by Letters Patent is L'The method of treating argentiferous lead ores containin sulfur for the economical production of lead products free from silver and of argentiferous products, which consists in subjecting the ore, mixed with carbon and without previous desulfurization, to a compound reducing and oxidizing treatment at comparatively low tempera-- 'ture in an open hearth furnace in order to produce argentiferous base bullion, gray slag and dust ,and alsonon-argentiferous lead and without previous desulfurization to a compound reducing and oxidizing treatment at comparatively low temperature in an open hearth furnace in order to roduce argentiferous base bullion, gray s ag and dust and also non-argentiferous lead fumes leaving the furnace in admixture with the dust and furnace gases, then causing the argentiferous dust to separate from the gases and lead fume by subsidence in a system of flues and settling chambers, then separating the lead fume from the gases by screening and then subjecting the lead fume to a compound reducing and oxidizing treatment at 1' gh temperature to produce from it sublimed white lead and pig lead.

.OLIVER H. PIOHER. Witnesses:

ARNOLD KATZ, D. STEWART. 

